1,005 research outputs found

    Uptake and accumulation of metals in Spartina alterniflora salt marshes from a South American estuary

    Get PDF
    Salt marshes are capable of reducing metal pollution in coastal waters, but this capacity is highly dependent on the metal, the physico-chemical characteristics of the sediment, the plant species, the production of biomass, the time of the year, etc. The aim of this study was to assess the uptake and accumulation of Pb, Ni, Cu and Zn in Spartina alterniflora from three salt marshes within the BahĂ­a Blanca estuary (BBE), a human-impacted Argentinean system. Metal concentrations in sediments and plants showed the same order at all sites: Zn > Cu > Pb ≄ Ni. The site with lower organic matter and fine sediment content had lower metal concentrations in the sediments, but not a lower metal content in the plant tissues, meaning that the sediment characteristics influenced the metal concentrations in the sediment and their uptake by plants. Despite differences in sediment characteristics between sites, metals were always higher in the belowground tissues than in aboveground ones and, in general, higher in dead than in live tissues. Some metals were accumulated in plant tissues, but not others, and this is dependent on the metal and the sediment characteristics. Allocation patterns of metals in tissues of S. alterniflora were mainly dependent on metal concentrations, determining higher belowground pools, but the aboveground pools were important in some cases due to higher biomass. Partitioning of metals in above or belowground pools determines their fate within the estuarine system, since tissues can decompose in situ (belowground) or be exported (aboveground). Seasonal dynamics were important for some variables but were less noticeable than the differences between sites and tissues. Our results indicate that S. alterniflora from the BBE is efficient in accumulating some metals, despite usually low metal concentrations in sediments and plants. This accumulation capacity has implications for the whole system through the fate of the tissues.Fil: Negrin, Vanesa Lorena. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - BahĂ­a Blanca. Instituto Argentino de OceanografĂ­a. Universidad Nacional del Sur. Instituto Argentino de OceanografĂ­a; Argentina. Universidad Nacional del Sur. Departamento de BiologĂ­a, BioquĂ­mica y Farmacia; ArgentinaFil: BottĂ©, Sandra Elizabeth. Universidad Nacional del Sur. Departamento de BiologĂ­a, BioquĂ­mica y Farmacia; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - BahĂ­a Blanca. Instituto Argentino de OceanografĂ­a. Universidad Nacional del Sur. Instituto Argentino de OceanografĂ­a; ArgentinaFil: la Colla, Noelia Soledad. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - BahĂ­a Blanca. Instituto Argentino de OceanografĂ­a. Universidad Nacional del Sur. Instituto Argentino de OceanografĂ­a; ArgentinaFil: Marcovecchio, Jorge Eduardo. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - BahĂ­a Blanca. Instituto Argentino de OceanografĂ­a. Universidad Nacional del Sur. Instituto Argentino de OceanografĂ­a; Argentina. Universidad TecnolĂłgica Nacional. Facultad Regional BahĂ­a Blanca; Argentina. Universidad FASTA "Santo Tomas de Aquino"; Argentin

    The constitution of a european demoi-cracy: Really a third way?

    Full text link
    Desarrollo una reflexiĂłn sobre la perspectiva polĂ­tico-social de una ConstituciĂłn europea basada en una demoi-cracia, destinada a examinar la viabilidad de una vĂ­a alternativa al federalismo y a un enfoque intergubernamental, hacia un equilibrio entre el concepto de nacional y europeo, dando lugar a una perspectiva que pone de manifiesto contradicciones de una propuesta que no desvĂ­a decididamente de modelos interestatales o federales. El demos es un grupo que autoriza un proceso de toma de decisiones colectivamente vinculante. Al demos soberano corresponde la acciĂłn de gobierno comĂșn que involucra el uso del poder del estado junto con los demĂĄs pueblos soberanos. Es preciso volver a la relaciĂłn entre pueblo y soberanĂ­a e investigar como esas nociones se construyan en una realidad social para llegar a una soberanĂ­a comĂșn (Cheneval y Nicolaidis, 2016), es decir, una demoicracy de demoi integrados. A nivel de UniĂłn Europea, las instituciones tienen como objetivo la democratizaciĂłn supranacional para cuya realizaciĂłn se necesita un ethos demoicratico. Sin embargo, la idea que admite que la UE constituye una tercera vĂ­a, alternativa a una Europa interestatal o federal, difĂ­cilmente parece resistirse ante la esfera pĂșblica europea, donde continĂșa sobreviviendo el choque entre las dinĂĄmicas indicadas (Ronzoni, 2016)The following contribution is aimed to reflect on the social-political perspective of a European Constitution based on a demoi-cracy, examining the feasibility of an alternative way to federalism and an intergovernmental approach, towards a balance between the concept of national and European, also making clear the contradictions of a proposal that does not take off in a resolutive way from interstate or federal models. Demos is a group of individuals that authorizes a collectively-binding decision-making process. To the sovereign demos rests the action of common government involving the use of the power of the state together with other sovereign peoples. It is necessary to return to the relationship between people and sovereignty and to ask how these notions can be built in a social reality to arrive to a common sovereignty (Cheneval and Nicolaidis, 2016),an European demoicracy of integrated demoi. Union-wide institutions aim at supranational democratisation for the realization of which a demoicratic ethos is needed. However, the idea that the EU constitutes a third way, alternative to an interstate or federal Europe, seems to be hardly resisting in the European public sphere, where it continue

    Does the thermal spike affect low-energy ion-induced interfacial mixing?

    Full text link
    Molecular dynamics simulations have been used to obtain the three-dimensional distribution of interfacial mixing and cascade defects in Ti/Pt multilayer system due to single 1 keV Ar+Ar^+ impacts at grazing angle of incidence. The Ti/Pt system was chosen because of its relatively high heat of mixing in the binary alloy and therefore a suitable candidate for testing the effect of heat of mixing on ion-beam mixing. However, the calculated mixing profile is not sensitive to the heat of mixing. Therefore the thermal spike model of mixing is not fully supported under these irradiation conditions. Instead we found that the majority of mixing occurs after the thermal spike during the relaxation process. These conclusions are supported by liquid, vacancy as well as adatom analysis. The interfacial mixing is in various aspects anomalous in this system: the time evolution of mixing is leading to a phase delay for Ti mixing, and Pt exhibits an unexpected double peaked mixing evolution. The reasons to these effects are discussed.Comment: 7 pages, 12 figures, Nucl. Instr. Meth. B211, 524. (2003

    Estradiol exerts antiapoptotic effects in skeletal myoblasts via mitochondrial PTP and MnSOD.

    Get PDF
    17beta-Estradiol (E2) protects several non-reproductive tissues from apoptosis, including skeletal muscle. We have shown that E2 at physiological concentrations prevented apoptosis induced by H2O2 in C2C12 skeletal myoblasts. As we also demonstrated the presence of estrogen receptors in mitochondria, the present work was focused on the effects of E2 on this organelle. Specifically, we evaluated the actions of E2 on the mitochondrial permeability transition pore (MPTP) by the calcein-acetoxymethylester/cobalt method using fluorescence microscopy and flow cytometry. Pretreatment with E2 prevented MPTP opening induced by H2O2, which preceded loss of mitochondrial membrane potential. In addition, it was observed that H2O2 induced translocation of Bax to mitochondria; however, in the presence of the steroid this effect was abrogated suggesting that members of the Bcl-2 family may be regulated by E2 to exert an antiapoptotic effect. Moreover, E2 increased mitochondrial manganese superoxide dismutase protein expression and activity, as part of a mechanism activated by E2 that improved mitochondrial performance. Our results suggest a role of E2 in the regulation of apoptosis with a clear action at the mitochondrial level in C2C12 skeletal myoblast cells.Fil: la Colla, Anabela Belén. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vasconsuelo, Andrea Anahi. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Boland, Ricardo Leopoldo. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Mitochondrial dysfunction and epigenetics underlying the link between early-life nutrition and non-alcoholic fatty liver disease

    Get PDF
    Early-life malnutrition plays a critical role in fetal development and predispose to the appearance of metabolic diseases in later life, according to the concept of 'developmental programming'. Different types of early nutritional imbalances, including undernutrition, overnutrition or micronutrient deficiency have been related to long-term metabolic disorders. Accumulating evidence has demonstrated that disturbances in nutrition during the period of preconception, pregnancy and primary infancy can affect mitochondrial function and epigenetic mechanisms. Moreover, even though multiple mechanisms underlying non-alcoholic fatty liver disease (NAFLD) have been described, in the last years special attention has been given to mitochondrial dysfunction and epigenetic alterations. Mitochondria play a key role in cellular metabolic functions. Dysfunctional mitochondria contribute to oxidative stress, insulin resistance and inflammation. Epigenetic mechanisms have been related to alterations in genes involved in lipid metabolism, fibrogenesis, inflammation and tumorigenesis. In accordance, studies have reported that mitochondrial dysfunction and epigenetics linked to early-life nutrition can be important contributing factors in the pathogenesis of NAFLD. In this review, we summarize the current understanding of the interplay between mitochondrial dysfunction, epigenetics and nutrition during early life, which is relevant to developmental programming of NAFLD.Fil: la Colla, Anabela Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Camara, Carolina Anahí. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Campisano, Sabrina Edith. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Chisari, Andrea Nancy. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentin

    In vitro antitumorsko i antivirusno djelovanje novih benzotiazola i 1,3,4-oksadiazol-2-tion derivata

    Get PDF
    A series of new benzothiazole derivatives 6a-h have been synthesized, in five steps, from substituted phenols via the 1,3,4-oxadiazole-2-thiones 5a-h. The in vitro antitumor activity of the compounds obtained was investigated and the benzothiazol derivatives 6d and 6e showed high effects on leukaemia cell lines CCRF-CEM (CC50 = 12 ± 2 ”mol L1, 8 ± 1 ”mol L1, respectively). These compounds are leading candidates for further development. The title compounds were tested against representatives of several virus families containing single stranded RNA genomes, either positive-sense (ssRNA+), or negative-sense (RNA-), and against double-stranded RNA genomes (dsRNA), as well as some Flaviviridae viruses.U pet reakcijskih koraka sintetizirana je serija novih derivata benzotiazola 6a-h polazeći iz supstituiranih fenola preko 1,3,4-oksadiazol-2-tiona 5a-h. Sintetizirani spojevi ispitani su na antitumorsko djelovanje. Benzotiazol derivati 6d i 6e pokazali su jak učinak na staničnu liniju leukemije CCRF-CEM (CC50 = 12 ± 2, odnosno 8 ± 1 ”mol L1). Ti su spojevi predvodni spojevi za daljnji razvoj. Nadalje, novi su spojevi testirani na djelovanje na nekoliko tipova virusa koji sadrĆŸe bilo pozitivni (ssRNA+) bilo negativni (RNA-) jednolančani RNA genom ili dvolančani RNA genom (dsRNA), te na neke Flaviviridae viruse

    Interplay between early-life malnutrition, epigenetic modulation of the immune function and liver diseases

    Get PDF
    Early-life nutrition plays a critical role in fetal growth and development. Food intake absence and excess are the two main types of energy malnutrition that predispose to the appearance of diseases in adulthood, according to the hypothesis of 'developmental origins of health and disease'. Epidemiological data have shown an association between early-life malnutrition and the metabolic syndrome in later life. Evidence has also demonstrated that nutrition during this period of life can affect the development of the immune system through epigenetic mechanisms. Thus, epigenetics has an essential role in the complex interplay between environmental factors and genetics. Altogether, this leads to the inflammatory response that is commonly seen in non-alcoholic fatty liver disease (NAFLD), the hepatic manifestation of the metabolic syndrome. In conjunction, DNA methylation, covalent modification of histones and the expression of non-coding RNA are the epigenetic phenomena that affect inflammatory processes in the context of NAFLD. Here, we highlight current understanding of the mechanisms underlying developmental programming of NAFLD linked to epigenetic modulation of the immune system and environmental factors, such as malnutrition.Fil: Campisano, Sabrina Edith. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Química; ArgentinaFil: la Colla, Anabela Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Química; ArgentinaFil: Echarte, Stella Maris. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Chisari, Andrea Nancy. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Química; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Química; Argentin
    • 

    corecore